Sinew backing Osage, 1st attempt &@$%@*(# 2#%&*^#%*!!!

[servicebeary]

well, #$^#$% *#^@$ #^$^$& $%%&^  ok, now I feel better.  So, there I was, all nine thousand bundles of sinew layed-out.  Hot glue and once again It's way to late for me to be working, so I wasn't thinking strait..and I don't think the literature mentions the dangers of trying to put sinew on in very dry cool conditions.  So anyhow, I dip the first bundle and take it out, lay it on the bow, and it's gelling already, so I kind of get it on evenly, but it's obvious that it's not adheared correctly, so I rip it off and try again.  I diluted the glue more, heated it up more and went at it again, and got slightly better results, so I was taking extra glue and working the edges where it was raised slightly, and after continually diluting it more and more, and more, and getting it pretty darn hot, I finished the first layer, 4 hours later, it was 1am   I went to sleep and it was pretty dang dry in the morning.  Actually in my 55 degree cabin (30 and dry as a bone outside) it was dry to the touch about 60 seconds after it touched the bow.  It was a nightmare getting it on there, and adding little bits of glue to smooth the spots that gel'd up before I could smooth them down.  So, by the next day I had the cabin up to 60 degrees, put a pot of water on the stove to raise the humidity and kept the glue thinner than the prescribed (thin syrup) at least that's how I see it, and I had better luck, but it still gel'd fast.  After 3-4 courses (I put more where I had hinged it) I was done, and it was dry to the touch within a few minutes. 
---if you made it this far you must love sinew  
--so, my main concern is that I didn't soak some of the first bundles as long as I should have (after that I learned to soak one while applying the other) and that was my major mistake.......so anyone think there's a prayer it's going to hang on there?  I did the acetone and boiling water, and the pre layer of glue, and let that dry a couple days...
..what a painful way to learn the ropes.., I won't be doing that again soon, or until tomorrow when I work that knotty service berry in the garage and it starts to crack
thanks if you read all that    -nick

[M-P]

Hi Nick,  I've sinewed a bunch of bows and I'm still not sure I have all the kinks worked out.   
Working in a warm room really helps!!   I can turn my little electric room heater up a 1/2 day ahead of time and work in 90= temperatures. 
First I dip the bundles in plain water and lay them out on a newspaper, ready to use.  Buy the time I've laid out ~ 1 layer's worth,  the first bundles will be nice and soft, but not too wet.  The glue was softened for at least one hour and then the glue pot turned on.  Each bundle is dipped in the glue and then repeatedly finger combed to straighten the threads and produce a nice flat ribbon.  Only then is the bundle laid on and smoothed out and then on to the next.
Ron

[El Destructo]

Nick...did you pre-moisten the Bundles with water first before dipping them in the Hide Glue? Also once a row of Sinew is applied ...it's going to look all swelled and lumpy...don't apply more Glue to make it look flat...you will end up with way too much Glue on each layer of Sinew...it takes days....sometimes weeks for the Sinew to shrink back and lay down flat...until then it will look like worms laying on the Back of the Bow!...I moisten the Bundles....pat them off well...then dip each one as I get ready to lay it out....then I take my Thumb and Pointer Finger...and squeeze all of the excess Glue off before I lay the Bundle down...and then I use my Finger Nail (if I haven't chewed them off this Month... ) to flatten the fibers down smoothly...and move on to the next Bundle...I know that here in the Texas Panhandle...where the Humidity is negligible (15-25 %) I have to thin my glue out just about as thin as Corn Oil...to keep it runny long enough to get the Sinew laying good....you will just have to play with it till you find a good happy medium for you and your area....and by all means ....do it early in the Day...not passed your Bedtime....

[Pappy]

I don't pre wet my sinew ,but I do have the glue pretty thin.Also you want the glue hot,but not to hot or it will cook the sinew and that ant a good thing.I dip it and like EL.squeeze out the access.If you get it to heavy it will crack and creak every time you pull the bow.I use a bone or horn tip to smooth it off.I also keep a pan of clean water to rinse my fingers between bundles. It is a lot of work,thats why I don't do many,never seen a big advantage on a normal bow.
   Pappy

[servicebeary]

thanks fellas, I just hope it stays on there at this point.  If it's noisy, at least with a 40 pounder I can draw it back real early and hold it til the deer gets close   If it's not so noisy that it spooks em from a long ways off.
- I didn't pre soak them, but I did like the TBB said, and a little more.  I let one bundle soak while I put one on, at least 30 seconds. Then I kind of got it strait with the help of the hot glue, but that was after I figure all that out, so my first, and most important layer, is my worst   maybe I should get religious real quick...
 I squeezed out most of the excess, so maybe I'll get lucky.  I was just wetting my fingers with a little glue and rubbing the areas that were sticking up or not soaked enough.

-- I know they say 10-14 days, but since it's super dry here...might it be dry sooner? 
      thanks again for all the advice, -nick     

[gstoneberg]

There's at least a decent chance it'll stick.  In my limited experience, if the bow back was degreased, lightly roughen'd, sized with glue, the sinew was well wetted with glue, the excess squeezed out as El D described, and the glue was not too hot; it has always stuck.  I have only built mulberry and osage bows though.   I totally ignore the wet look and wrap the bow in an ace bandage as soon as I finish the sinew job and leave it on for 24 hours.  It really smooths it out.  Leave it on too long though and you'll be sorry and have to scrape fibers off.  I always give the bow 2 weeks of drying time unless I intend to add more sinew.   I don't find applying sinew to be a big hassle at all.  Takes me about an hour to do a bow.  What I do find a hassle is pounding all those tendons and separating the fibers into bundles.  I had a friend up north that sat on a dredge at work all day bored stiff.  He would pound my sinew for me to pass the time.  I'm sure sorry he's not down here in Texas.  Not sure I'll do as much sinew backing if I have to pound it.

George

[servicebeary]

wow, an hour?  How many layers is that?  It took me about 7 hours for about 4 layers

[sonny]

about the quickest I've ever been able to sinew back a bow was four hours.
that was using really long moose sinew fibers.

...and it seems that I usually have to go back in fill in a couple o' gaps here and there.

[JackCrafty]

Two words:

FISH GLUE

Fish glue has a good amount of "open" time and will be fluid at 60^oF (no heating required).  It takes me about an hour or two per layer depending on how fat the sinew strand are.  I also pre-wet my sinew but only as much as I'll need for 10 minutes at a time.

The biggest differences I've found is that fish glue is more brittle than hide glue and is quite a bit more expensive...and astronomically more expensive compared to knox.

[gstoneberg]

wow, an hour?  How many layers is that?  It took me about 7 hours for about 4 layers

Sorry, I should have been more specific.  The bow I did in an hour was a single layer of sinew.  2 layers would be double that.  The only time I did 4 layers of sinew I did it in 2 sessions.  I'm not going to do that again.  It's no wonder your glue was setting up on you.  I also think it will take longer to dry with that much wet sinew on the bow back.  I'm curious why you went with 4 layers of sinew?  It adds a lot of weight and will make the bow sluggish and add hand shock if you aren't careful.  I use it to protect the bow back if I think there's a flaw in the wood that might cause problems.  If I'm going to put snakeskin on the bow I nearly always sinew back since I'm going to mess with hide glue anyway (and I hate to have a good snakeskin ruined by a broken bow ).  George

[servicebeary]

well, I undershot my weight goal by a lot, and TBB1 said 3-4 layers is a good starting point....  I was kinda questioning that logic myself, but I am hoping to gain 10 pounds so hopeful between the sinew and the heat treated belly it will pull 40+ lbs.  It does feel like the tiny bow has doubled in weight
   appreciate the advice -nick   

[ricktrojanowski]

I've only sinewed one bow,  I have another to do in the near future.  My advice is don't worry about how long it takes.  Just worry about doing a good job.  I did 2 layers let it dry for a month or so then added 1 full layer and a crowning layer.  Also clean hands are key.  Keep LOTS of clean warm water available and constantly clean your hands.

[rileyconcrete]

I think you will be fine.  I did a short west coast style bow, only two layers of sinew on some elm I had, and It was more of a learning bow than anything and I cant get the sinew to pull up, it stuck really good and I didnt really know what I was doing. It turned out great also.

The bow was 38 inches long. It gained 14 pounds with two layers of sinew.  It finished at 68 Lbs at 19"

Tell
.

[gstoneberg]

That's interesting, I've never seen a significant weight gain out of 2 layers of sinew.  I usually get an inch or two of reflex in the limbs, but that normally comes back out as the bow is shot in.  The end result for me is a bow with little or no set that is nearly unbreakable from the back.  I usually don't decide to sinew back until I see how the bow is looking at about 1/2 draw.  If I see something that makes me suspect the back could fail I stop at that point and sinew.  If not, like Pappy, I'd rather make an unbacked bow.  In a climate where the humidity goes up in the summer, sinew backed bows get a little sluggish with the high humidity.  The last one I made went down close to Houston, TX.  I'll be curious how it acts for him this summer.

I personally don't care how my sinew job looks as I always cover sinew with something (normally snakeskin).  However, I left one uncovered early in my bow making career and everybody at the local archery club thought I'd backed it with bark.  I guess it isn't that obvious to the average person and the deer I killed with it didn't seem to notice.   With a little stain or paint it would look a lot like bark.  The finish would have to be good though to keep moisture from attacking the glue.

George

[El Destructo]

I'm with you George...I have never seen more than a 10 pound increase with three layers of Sinew....just a good bulletproof Bow....JMO